Eat the pie or imbibe the ribbon: An epochal moment at the crossroads of mechanized cataract surgery

Abstract

Dear Editor, The femtosecond laser lens fragmentation (LLF) has opened new vistas for decreasing the energy used in removing cataracts. Batlle et al., have reported a decrease of 40% in the cumulative dispersive energy (CDE) for phacoemulsification in their study comparing non-laser assisted manual phacoemulsification (18.9 s) with laser lens fragmentation (LLF) assisted phacoemulsification (11.6 s).[1] Edwards et al., have shown that the decrease in CDE was related to nuclear density with a reduction of 100% for grade 1 nuclear cataract, 64% for grade 2, 39% for grade 3, and 42% for grade 4 cataracts. The study used pie-cut method of LLF disassembly.[2] Customizable LLF algorithms can be programmed on the femtosecond laser platform software. The developments on microsensors and controlling chips are already advanced enough to allow for precise control of pressure changes in medium flow systems. Given the current developments and the fact that the phacoemulsification systems today routinely use 3.2 or 2.8 mm entry ports, the need for using phacoemulsification with LLF would become redundant if the nucleus were to be fragmented in ribbon shapes [Fig 1]. The pie is unevenly shaped and is not suited to aspiration with a narrow and a very broad end. Our experience with the phacoemulsification machines has brought us to the point where we are comfortable with much higher vacuum pressures than, say, 2 decades ago. If power mode were to be dispensed within favor of a divided flow system and pure aspiration mode with chop being the preferred modality for preaspiration completion of lens fragmentation; then the 2.8 mm incision or even smaller incision with narrower ribbon blocks can remove the cataract with aspiration alone without any need for ultrasonic power delivery inside the eye. Figure 1 Aspiration through 3.2 mm incision with larger aspiration port using ribbon laser lens fragmentation (LLF) and chop parameters. The irrigation is through side port entry in the divided system for better chamber stability Increasing the bore of aspiration port increases the effective vacuum (or holding power) and decreases rise time in the system. All this necessitates the use of a high inflow system and use of microsensors for fluidic control monitoring vacuum at level of handpiece itself to guard against sudden decompression. This brings down the cost of peripheral system. Thus, the capital and running cost of femtosecond platform become the main limiting parameters in the economic consideration. Are we looking at an age without the ubiquitous “ultrasonic phaco”? Only time can tell, whether or when these random musings will become a reality. However, one thing is sure. This is truly an epochal moment at the crossroads for mechanized cataract surgery.